This feature can be toggled on and off by a host while in the conference: Follow My Layout

We feel its more intuitive for this feature to be enabled by default for the conference owner's account so that the participants in their meeting room will see exactly what the host wants them to see. Note that promoted hosts or those who supply the conference host password can enable this option, but it is not enabled for them by default.

It should also be noted that this is a per-host setting, meaning each host in the conference can enable or disable this at their leisure. Multiple hosts should not enable this feature concurrently.